* Leaking fluid: This is a sign that the seals on the shocks are worn out and they are no longer able to hold in the fluid.
* Sagging or bouncing: This can indicate that the shocks are no longer able to properly support the weight of the truck.
* Uneven tire wear: This can be caused by worn shocks that are not able to properly control the movement of the wheels.
* A rough ride: This can be caused by worn shocks that are no longer able to dampen the bumps and vibrations from the road.
It is important to change shocks on a semi truck as soon as they start to show signs of wear or damage. This will help to prevent further damage to the truck and improve the safety and ride quality.
The frequency with which shocks need to be changed on a semi truck will depend on a number of factors, including the type of truck, the driving conditions, and the load weight. However, as a general rule, shocks should be changed every 100,000 miles or so.